<!DOCTYPE html>
<style>
.multicol {
    width: 60px;
    -webkit-column-width: 20px;
    -webkit-column-gap: 0;
    column-fill: auto;
    height: 60px;
    line-height: 20px;
}
.square {
    width: 20px;
    height: 20px;
    background: red;
}
.layer { transform: translateY(20px); will-change: transform; }
.layer .square { background: green; }
</style>

<p>There should be two small green squares vertically aligned below, and another red square to the top-right. The second green square does not overlap the red because it is conmposited, and hence not fragmented.</p>
<div class="multicol">
    <br>
    <br>
    <br>
    <br>
    <br>
    <div class="layer"> <!-- from second to third column -->
        <div class="square"></div>
        <br>
        <div class="square"></div>
    </div>
    <div class="square"></div>
</div>
